US6010930A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vertically oriented structure with sloped opening and method for etching
Assignee: Micron Technology Inc
•
Filing: 1997-09-11
•
Granted: 2000-01-04
•
Expires: 2017-09-11
Abstract
Abstract Disclosed is a vertically oriented capacitor structure, which is of particular usefulness in MOS DRAM memory modules. The structure has upper and lower polysilicon capacitor plates separated by a dielectric layer, each of the plates and dielectric layers sloping at an angle with of about 80-85 degrees with respect to an underlying silicon substrate. As such, the novel capacitor is formed in a sloped contact opening. The contact area of electrical connection of the lower capacitor plate with an underlying active region has a sufficiently small horizontal cross-section that the contact area will not extend laterally beyond the active region and leakage will not occur. A method for forming the contact opening is disclosed and comprises first, the formation of an active region, preferably located between two insulating bird's beak regions, and covering the active area with a thin layer of oxide etch barrier material. A polysilicon layer is then formed above the oxide etch barrier. The etch is subsequently performed with the use of a diatomic chlorine etchant. Four embodiments are disclosed as variations on the step of etching the polysilicon with the diatomic chlorine etch chemistry.
Inventors
- 👤 David J. Keller
- 👤 Louie Liu
- 👤 Kris K. Brown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:42
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/692; H10D1/711; H10D1/716; H10B; H10B12/00; H10B12/01; H10B12/02; H10B12/03; H10B12/033; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/268; Y; Y10; Y10S; Y10S148/00; Y10S148/014; Y10S438/00; Y10S438/978
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
59 words
A method for forming a sloped structure comprising: providing a layer of polysilicon substantially defining a plane and being formed over a substrate; and etching an opening in the layer of polysilicon using an etch chemistry comprising Cl 2 , such that the opening has a substantially straight sidewall set at a sloped angle with respect to the plane.
Claim 2
Independent Claim
59 words
A method for forming a sloped structure comprising: providing a layer of polysilicon substantially defining a plane and being formed over a substrate; and etching an opening in the layer of polysilicon using an etch chemistry comprising Cl 2 , such that the opening has a substantially straight sidewall set at a sloped angle with respect to the plane.
Claim 3
Dependent Claim
16 words
A method as recited in claim 1, wherein the opening extends through the layer of polysilicon.
Claim 4
Dependent Claim
21 words
A method as recited in claim 1, wherein the opening extends through the layer of polysilicon and terminates at the substrate.
Claim 5
Dependent Claim
14 words
A method as recited in claim 1, wherein the substrate is a semiconductor substrate.
Claim 6
Dependent Claim
28 words
A method as recited in claim 1, wherein the sloped angle is in a range from about 80 degrees to about 85 degrees with respect to the substrate.
Claim 7
Independent Claim
79 words
A method for forming a sloped opening in a non-oxide material, the method comprising: providing a substrate; forming an oxide layer on the substrate; forming a layer of the non-oxide material on the oxide layer; and etching an opening in the layer of the non-oxide material extending to the oxide layer by using an etch chemistry comprising Cl 2 , such that the opening has a substantially straight sidewall set at a sloped angle with respect to the substrate.
Claim 8
Independent Claim
79 words
A method for forming a sloped opening in a non-oxide material, the method comprising: providing a substrate; forming an oxide layer on the substrate; forming a layer of the non-oxide material on the oxide layer; and etching an opening in the layer of the non-oxide material extending to the oxide layer by using an etch chemistry comprising Cl 2 , such that the opening has a substantially straight sidewall set at a sloped angle with respect to the substrate.
Claim 9
Dependent Claim
36 words
A method as recited in claim 6, wherein the substrate substantially defines a plane and wherein the sloped angle is in a range from about 80 degrees to about 85 degrees with respect to the plane.
Claim 10
Dependent Claim
22 words
A method as recited in claim 6, wherein the etch chemistry further comprises a passivating gas mixed with the Cl 2 .
Claim 11
Dependent Claim
15 words
A method as recited in claim 8, wherein the passivating gas comprises N 2 .
Claim 12
Dependent Claim
15 words
A method as recited in claim 8, wherein the passivating gas comprises O 2 .
Claim 13
Dependent Claim
15 words
A method as recited in claim 8, wherein the passivating gases comprise HeO 2 .
Claim 14
Dependent Claim
14 words
A method as recited in claim 6, wherein the etch chemistry further comprises HBr.
Claim 15
Dependent Claim
16 words
A method as recited in claim 12, wherein the etch chemistry further comprises a passivating gas.
Claim 16
Dependent Claim
15 words
A method as recited in claim 13, wherein the passivating gas comprises N 2 .
Claim 17
Dependent Claim
15 words
A method as recited in claim 13, wherein the passivating gas comprises O 2 .
Claim 18
Dependent Claim
20 words
A method as recited in claim 6, wherein etching the opening is conducted with a magnetically enhanced reactive ion etcher.
Claim 19
Dependent Claim
124 words
A method as recited in claim 16, wherein etching the opening comprises: exposing the layer of the non-oxide material to Cl 2 at a pressure in a range from about 1 millitorr to about 100 millitorr, at a power in a range from about 200 Watts to about 700 Watts, and a magnetic field in a range from about 50 Gauss to about 100 Gauss; and exposing the layer of the non-oxide material to both of Cl 2 and HeO 2 at a pressure in a range from about 1 millitorr to about 100 millitorr, at a power in a range from about 50 watts to about 200 Watts, and a magnetic field in a range from about 50 Gauss to about 100 Gauss.
Claim 20
Dependent Claim
65 words
A method as recited in claim 16, wherein: the etch chemistry further comprises a passivating gas; and etching the opening is conducted at a pressure in a range from about 1 millitorr to about 100 millitorr, at a power in a range from about 200 Watts to about 700 Watts, and a magnetic field in a range from about 50 Gauss to about 100 Gauss.
Claim 21
Dependent Claim
18 words
A method as recited in claim 6, wherein etching the opening is conducted with a reactive ion etcher.
Claim 22
Dependent Claim
18 words
A method as recited in claim 6, wherein etching the opening is conducted with a high density etcher.
Claim 23
Dependent Claim
83 words
A method as recited in claim 20, wherein: the etch chemistry further comprises a passivating gas; and etching the opening is conducted at a bias power applied at a bottom portion of a chamber of the high density etcher in a range from about 10 Watts to about 300 Watts, and at a wide range of top power applied to a top portion of the chamber of the high density etcher chamber in a range from about 100 Watts to about 3000 Watts.
Claim 24
Independent Claim
125 words
A method for forming a contact opening for a semiconductor device, said method comprising: providing a semiconductor substrate substantially defining a plane; forming an active region in the semiconductor substrate; providing an oxide layer on the semiconductor substrate; providing a layer of a non-oxide material over the oxide layer; etching the contact opening through the layer of the non-oxide material using a chemical etchant comprising Cl 2 together with a passivating gas such that the contact opening etched thereby has a substantially straight sidewall set at a sloped angle in a range from about 80 degrees to about 85 degrees with respect to the plane; and etching through the oxide layer using a carbon-containing fluorine chemistry to extend the contact opening to the active region.
Claim 25
Independent Claim
125 words
A method for forming a contact opening for a semiconductor device, said method comprising: providing a semiconductor substrate substantially defining a plane; forming an active region in the semiconductor substrate; providing an oxide layer on the semiconductor substrate; providing a layer of a non-oxide material over the oxide layer; etching the contact opening through the layer of the non-oxide material using a chemical etchant comprising Cl 2 together with a passivating gas such that the contact opening etched thereby has a substantially straight sidewall set at a sloped angle in a range from about 80 degrees to about 85 degrees with respect to the plane; and etching through the oxide layer using a carbon-containing fluorine chemistry to extend the contact opening to the active region.
Claim 26
Dependent Claim
64 words
A method as recited in claim 22, wherein etching the contact opening is conducted in a magnetically enhanced reactive ion etcher at a pressure in a range from about 1 millitorr to about 100 millitorr, at a power in a range from about 50 Watts to about 200 Watts, and a magnetic field in a range from about 50 Gauss to about 100 Gauss.
Claim 27
Dependent Claim
94 words
A method as recited in claim 22, wherein etching the contact opening is conducted in a high density etcher at a bias power applied at a bottom portion of a chamber of the high density etcher in a range from about 10 Watts to about 300 Watts, at a wide range of top power applied to a top portion of the chamber of the high density etcher chamber in a range from about 100 Watts to about 3000 Watts, and at a pressure in a range from about 1 millitorr to about 100 millitorr.
Claim 28
Independent Claim
168 words
A method for forming an opening in a layer of a non-oxide material, the method comprising: providing a semiconductor substrate; forming an oxide layer on the semiconductor substrate; forming a layer of a non-oxide material on the oxide layer; and etching an opening in the layer of the non-oxide material in a magnetically enhanced reactive ion etcher, wherein: the non-oxide material is exposed to Cl 2 at a pressure in a range from about 1 millitorr to about 100 millitorr, at a power in a range from about 200 Watts to about 700 Watts, and with a magnetic field in a range from about 50 Gauss to about 100 Gauss; and the non-oxide material is exposed to both of Cl 2 and HeO 2 at a pressure in a range from about 1 millitorr to about 100 millitorr, at a power in a range from about 50 Watts to about 200 Watts, and with a magnetic field in a range from about 50 Gauss to about 100 Gauss.
Claim 29
Independent Claim
168 words
A method for forming an opening in a layer of a non-oxide material, the method comprising: providing a semiconductor substrate; forming an oxide layer on the semiconductor substrate; forming a layer of a non-oxide material on the oxide layer; and etching an opening in the layer of the non-oxide material in a magnetically enhanced reactive ion etcher, wherein: the non-oxide material is exposed to Cl 2 at a pressure in a range from about 1 millitorr to about 100 millitorr, at a power in a range from about 200 Watts to about 700 Watts, and with a magnetic field in a range from about 50 Gauss to about 100 Gauss; and the non-oxide material is exposed to both of Cl 2 and HeO 2 at a pressure in a range from about 1 millitorr to about 100 millitorr, at a power in a range from about 50 Watts to about 200 Watts, and with a magnetic field in a range from about 50 Gauss to about 100 Gauss.
Claim 30
Independent Claim
114 words
A method for forming an opening in a layer of a non-oxide material, the method comprising: providing a semiconductor substrate; forming an oxide layer on the semiconductor substrate; forming a layer of a non-oxide material on the oxide layer; and etching an opening in the layer of the non-oxide material in a magnetically enhanced reactive ion etcher, wherein the non-oxide material is exposed to Cl 2 and a passivating gas at a pressure in a range from about 1 millitorr to about 100 millitorr, at a power in a range from about 200 Watts to about 700 Watts, and with a magnetic field in a range from about 50 Gauss to about 100 Gauss.
Claim 31
Independent Claim
114 words
A method for forming an opening in a layer of a non-oxide material, the method comprising: providing a semiconductor substrate; forming an oxide layer on the semiconductor substrate; forming a layer of a non-oxide material on the oxide layer; and etching an opening in the layer of the non-oxide material in a magnetically enhanced reactive ion etcher, wherein the non-oxide material is exposed to Cl 2 and a passivating gas at a pressure in a range from about 1 millitorr to about 100 millitorr, at a power in a range from about 200 Watts to about 700 Watts, and with a magnetic field in a range from about 50 Gauss to about 100 Gauss.
Claim 32
Independent Claim
55 words
A method for forming an opening in a layer of a non-oxide material, the method comprising: providing a semiconductor substrate; forming an oxide layer on the semiconductor substrate; forming a layer of a non-oxide material on the oxide layer; and etching an opening in the layer of the non-oxide material in a reactive ion etcher.
Claim 33
Independent Claim
55 words
A method for forming an opening in a layer of a non-oxide material, the method comprising: providing a semiconductor substrate; forming an oxide layer on the semiconductor substrate; forming a layer of a non-oxide material on the oxide layer; and etching an opening in the layer of the non-oxide material in a reactive ion etcher.
Claim 34
Independent Claim
122 words
A method for forming an opening in a layer of a non-oxide material, the method comprising: providing a semiconductor substrate; forming an oxide layer on the semiconductor substrate; forming a layer of a non-oxide material on the oxide layer; and etching an opening in the layer of the non-oxide material in a high density etcher, wherein etching the opening is conducted at a bias power applied at a bottom portion of a chamber of the high density etcher in a range from about 10 Watts to about 300 Watts, and at a wide range of top power applied to a top portion of the chamber of the high density etcher chamber in a range from about 100 Watts to about 3000 Watts.
Claim 35
Independent Claim
122 words
A method for forming an opening in a layer of a non-oxide material, the method comprising: providing a semiconductor substrate; forming an oxide layer on the semiconductor substrate; forming a layer of a non-oxide material on the oxide layer; and etching an opening in the layer of the non-oxide material in a high density etcher, wherein etching the opening is conducted at a bias power applied at a bottom portion of a chamber of the high density etcher in a range from about 10 Watts to about 300 Watts, and at a wide range of top power applied to a top portion of the chamber of the high density etcher chamber in a range from about 100 Watts to about 3000 Watts.
Claim 36
Independent Claim
83 words
A method for forming a sloped structure comprising: providing a layer of a non-oxide material formed over a substrate the layer of said non-oxide material substantially defining a plane; and etching an opening in the layer of the non-oxide material using an etch chemistry comprising Cl 2 , such that the opening has a substantially straight sidewall set at a sloped angle with respect to the plane, wherein the opening extends through the layer of the non-oxide material and terminates at the substrate.
Claim 37
Independent Claim
83 words
A method for forming a sloped structure comprising: providing a layer of a non-oxide material formed over a substrate the layer of said non-oxide material substantially defining a plane; and etching an opening in the layer of the non-oxide material using an etch chemistry comprising Cl 2 , such that the opening has a substantially straight sidewall set at a sloped angle with respect to the plane, wherein the opening extends through the layer of the non-oxide material and terminates at the substrate.
Claim 38
Dependent Claim
15 words
A method as recited in claim 29, wherein the non-oxide material is a silicon-containing material.
Claim 39
Dependent Claim
13 words
A method as recited in claim 30, wherein the silicon-containing material is polysilicon.
Claim 40
Independent Claim
88 words
A method for forming a sloped structure comprising: providing a layer of a non-oxide material formed over a substrate, the layer of said non-oxide material substantially defining a plane; and etching an opening in the layer of the non-oxide material using an etch chemistry comprising Cl 2 , such that the opening has a substantially straight sidewall set at a sloped angle with respect to the plane, wherein the sloped angle is in a range from about 80 degrees to about 85 degrees with respect to the substrate.
Claim 41
Independent Claim
88 words
A method for forming a sloped structure comprising: providing a layer of a non-oxide material formed over a substrate, the layer of said non-oxide material substantially defining a plane; and etching an opening in the layer of the non-oxide material using an etch chemistry comprising Cl 2 , such that the opening has a substantially straight sidewall set at a sloped angle with respect to the plane, wherein the sloped angle is in a range from about 80 degrees to about 85 degrees with respect to the substrate.
Claim 42
Dependent Claim
15 words
A method as recited in claim 32, wherein the non-oxide material is a silicon-containing material.
Claim 43
Dependent Claim
13 words
A method as recited in claim 33, wherein the silicon-containing material is polysilicon.
Claim 44
Independent Claim
80 words
A method for etching a recess in a layer of polysilicon that defines a plane and is formed over a substrate, the method comprising the steps of: exposing the layer of the polysilicon to an etch chemistry comprising Cl 2 ; etching a recess into the layer of polysilicon, the recess having a substantially straight sidewall that is set at an acute angle with respect to the plane, wherein said step of etching is accomplished by said step of exposing.
Claim 45
Independent Claim
80 words
A method for etching a recess in a layer of polysilicon that defines a plane and is formed over a substrate, the method comprising the steps of: exposing the layer of the polysilicon to an etch chemistry comprising Cl 2 ; etching a recess into the layer of polysilicon, the recess having a substantially straight sidewall that is set at an acute angle with respect to the plane, wherein said step of etching is accomplished by said step of exposing.
Claim 46
Dependent Claim
19 words
The method as defined in claim 35, wherein said step of etching is performed in a reactive ion etcher.
Claim 47
Dependent Claim
21 words
The method as recited in claim 35, wherein the recess extends through the layer of polysilicon and terminates at the substrate.
References Cited (Backward Citations)
US4694561A
Cited
US4784720A
Cited
US4726879A
Cited
US5472564A
Cited
US4951175A
Cited
US5354716A
Cited
US5487811A
Cited
US5242536A
Cited
US5256245A
Cited
US5423941A
Cited
US5522966A
Cited
US5444013A
Cited
US5652170A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-01-03 | 2003-07-05 | 2004-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-01-03 | 2007-07-05 | 2008-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-01-03 | 2011-07-05 | 2012-01-04 | $7700.00 | Window Closed / Lapsed |